1. Field of the Invention
The present invention relates to an image forming apparatus, such as a printer, a copy machine and a facsimile machine, with an image reading unit.
2. Description of Related Art
FIG. 1 and FIG. 2 respectively show a conventional facsimile machine and a copy machine respectively disclosed in Japanese Patent Laid Open Applications No. 2-166962 and No. 2-17466. In the image forming apparatus such as the conventional facsimile machine and copy machine, a feed path 101 through which documents to be read are fed and a feed path 103 through which recording papers are fed to an image forming unit 102 are separated from each other. That is, the conventional image forming apparatus is provided with the two feed paths 101 and 103 respectively corresponding to an image reading process and an image forming process.
To achieve down sizing of the image forming apparatus with the image reading unit, the applicant has proposed that a feed path be used for two purposes; first, to feed documents to be read by an optical sensor, and second, to feed recording papers on which images are to be formed by an image forming unit (not published). However, as the feed path is used for feeding both documents and recording papers, if errors are made in operations, images may be formed, by mistake, on documents to be read. In this case, the documents are spoiled.